Liberal Democrat leader Charles Kennedy has been stressing his party's achievements in Scotland, after laughing off concerns about his health.

Mr Kennedy assured activists at the Scottish party conference that he was well and enjoying the Tayside air.

On Thursday, Mr Kennedy pledged he would get fitter and inject more energy into his leadership.

The Lib Dem leader blamed a stomach bug for missing the Budget and showed signs of illness during a speech on Sunday.

Mr Kennedy opened his address in Dundee with a joke about the outbreak of sweating as he delivered last Sunday's speech.

He told delegates that Scottish leader Jim Wallace used to stress that politics was as much about perspiration as inspiration.

"I never realised, until I got off my sickbed last weekend to deliver a certain party address in Southport, just how telling that observation was going to prove to be," he said.

At last, at last, the real prospect of fair votes electing truly representative local authorities up and down the breadth of the land

Charles Kennedy

Mr Kennedy then moved to focus on the performance of the Liberal Democrats as a party of government in the Scottish Executive.

He described the backing of proportional representation for local government elections in Scotland as a move that would "transform our system of democracy".

He said: "At last, at last, the real prospect of fair votes electing truly representative local authorities up and down the breadth of the land."

His address also included a defence of the party's position on Iraq, a call to get "tough without being illiberal" on crime, a reminder of the importance of the environmental agenda and a call to replace council tax with local income tax.

On devolution, Mr Kennedy urged that the political process should keep developing, raising the prospect of a fresh constitutional convention.

"Let it roll, let it roll," he said.

Mr Kennedy arrived in Dundee with his wife Sarah

"There is no reason at all why we shouldn't be willing constantly to update and renew."

The speech came as the party in Scotland is under pressure over its direction in coalition government.

Some members fear the party is in danger of abandoning its principles.

Some activists believe that has come at too high a price and that the party is in danger of making too many compromises on issues like criminal justice, the environment and higher education.

There was also concern that the conference would be overshadowed by speculation about Mr Kennedy's health.

Asked if he was tired with questions about his health as he arrived in Dundee, he joked: "I think it's touching - I did not know there was such spontaneous interest in my well-being."

All eyes were on the federal leader when he took to the stage on Friday afternoon, after he spent two days trying to reassure his Westminster colleagues that he is fit for the job.

He said he now intends to use Westminster's Easter break to get back to full strength with some hill walks.